The present invention relates to the use of cyclic depsipeptides, in particular 24-membered cyclodepsipeptides, for controlling ectoparasites, and to ectoparasiticidal compositions which comprise the depsipeptides.
Cyclic depsipeptides, and their preparation and use as parasiticides against helminths, nematodes and trematodes in animals (endoparasiticides) have already been the subject of numerous publications.
Known is, for example, a cyclodepsipeptide with the name PF 1022A and its action against endoparasites (EP-A 382 173 and EP-A 503 538). Further cyclic depsipeptides (cyclooctadepsipeptides: WO 98/55 469; WO 98/43 965; WO 93/19 053; EP-A 634 408; WO 94/19 334; WO 95/07 272; EP-A 626 375; EP-A 626 376; EP-A 664 297; EP 634 408; EP-A 718 298; WO 97/09 331; cyclohexadepsipeptides: WO 93/25 543; WO 95/27 498; EP-A 658 551; cyclotetradepsipeptides: EP-A 664 297; dioxomorpholines: WO 96/38 165: JP 08 225 552) and open-chain depsipeptides (EP-A 657 171; EP-A 657 172; EP-A 657 173; WO 97/07 093) and their endoparasiticidal action have been described.
Furthermore, it is already known that certain 24-membered cyclodepsipeptides, for example bassianolide and PF1022A, have insecticidal activity against silkworms (cf. M. Kanaoka et al., Agric. Biol. Chem. 43 (5), 1979, pp. 1079-83; JP 05 271 013).
However, the insecticidal activity of the prior-art compounds is, in particular at low application rates and concentrations, not entirely satisfactory in all areas of use. Futhermore, their use against ectoparasites, for example ticks, fleas and mites, has hitherto not been disclosed.
The present application provides:
Method of use of cyclooctadepsipeptides of the formula (I) 
in which
R1 represents hydrogen, C1-4-alkyl, in particular methyl, hydroxyl, halogen, in particular fluorine, C1-4-alkoxy, in particular methoxy or tert-butyloxy, C1-4-alkoxy-C1-4-alkyl, in particular methoxymethyl, ethoxyethyl, heterocyclylmethyl, in particular pyridylmethyl, tetrahydrofuranylmethyl, pyrrolidinylmethyl, furylmethyl, thienylmethyl, heteroaryl-C1-2-alkoxy, in particular pyridyl-methoxy, tetrahydrofuryl-methoxy, pyrrolidinyl-methoxy and furyl-methoxy, nitro, xe2x80x94NR3R4, xe2x80x94SO2xe2x80x94NR3R4,
R2 represents hydrogen, C1-4-alkyl, in particular methyl, hydroxyl, halogen, in particular fluorine, C1-4-alkoxy, in particular methoxy or tert-butyloxy, C1-4-alkoxy-C1-4-alkyl, in particular methoxymethyl, ethoxyethyl, heterocyclylmethyl, in particular pyridylmethyl, tetrahydrofuranylmethyl, pyrrolidinylmethyl, furylmethyl, thienylmethyl, heteroaryl-C1-2-alkoxy, in particular pyridyl-methoxy, tetrahydrofuranyl-methoxy, pyrrolidinyl-methoxy and furyl-methoxy, nitro, xe2x80x94NR3R4, xe2x80x94SO2xe2x80x94NR3R4,
R3 and R4 independently of one another each represent hydrogen, optionally substituted C1-4-alkyl, formyl, C1-4-alkoxycarbonyl, optionally substituted arylmethyl, in particular benzyl, or heterocyclylmethyl, in particular pyridylmethyl, tetrahydrofuranylmethyl, pyrrolidinylmethyl, furylmethyl, thienylmethyl,
R3 and R4 together with the nitrogen atom to which they are attached represent an optionally substituted mono- or polycyclic, optionally bridged and/or spirocyclic, saturated or unsaturated heterocycle which may contain one to three further heteroatoms from the group consisting of nitrogen, oxygen and sulphur,
X1, X2, X3 and X4 independently of one another represent oxygen or sulphur,
where, if R1 and R2 simultaneously represent hydrogen, at least one of the radicals X1, X2, X3 and X4 represents sulphur.
Depending on the nature of the substituents, the compounds of the general formula (I) can be present as geometrical and/or optical isomer mixtures of varying compositions. The invention relates both to the pure isomers and to the isomer mixtures.
The formula (I) provides a general definition of the cyclooctadepsipeptides which can be used according to the invention.
The substituents R1 and R2 are preferably in the para- or ortho-position. Particular preference is given to the para-position.
The substituents X1, X2 and X3 preferably represent oxygen, the substituent X4 preferably represents oxygen or sulphur.
Compounds of the general formula (I) which can be used according to the invention and which may be mentioned are, in particular, the compounds of the formula (II) below known from the PCT applications WO 93/19 053, WO 97/11 064 and EP-A 634 408 A1: 
in which
R1 and R2 represent identical or different radicals from the group consisting of hydrogen, N-morpholino, nitro, amino, mono- and dimethylamino, furylmethoxy, tetrahydrofurylmethoxy, pyrrolidinylmethoxy or pyridylmethoxy, but do not simultaneously represent hydrogen.
Furthermore, mention may be made of the compounds known from the PCT application WO 94/19 334.
Particular mention may be made of the compounds, known from the PCT applications WO 94/19 334 and WO 97/11 064, of the formula (III) below 
in which
R2 represents hydroxy, methoxy or tert-butoxy and furylmethoxy.
Finally, mention may be made of the prior-art compounds known from the PCT application WO 95/07 272.
The generic formulae and definitions described in these publications, and the individual compounds described therein, are explicitely incorporated herein by way of reference.
Furthermore and in particular, as compounds of the general formula (I) which can be used according to the invention and in which at least one of the substituents X1, X2 and X3 and/or X4 represents sulphur, mention may be made of the cyclic depsipeptides of the general formula (IV) and (V): 
in which
R1 and R2 represent identical or different radicals from the group consisting of hydrogen. N-morpholino, nitro, amino, mono- and dimethylamino, furylmethoxy, tetrahydrofurylmethoxy, pyrrolidinomethoxy or pyridylmethoxy.
The cyclic depsipeptides of the general formula (IV) and (V) form part of the subject-matter of a patent application of the applicant, which is a prior publication (cf. WO 98/43 965). These compounds are prepared by thionating compounds of the formula (I) in which X1, X2 and X3 and X4 represent oxygen with a suitable sulphurizing agent in the presence of diluent. Reference is made here to the corresponding Preparation Examples further below.
The cyclic depsipeptides which can be used according to the invention are suitable for controlling animal pests, such as arthropods, preferably insects, arachnids, encountered in animal husbandry and livestock breeding, in productive livestock, breeding stock, zoo animals, laboratory animals, animals used in experiments and pets, and have low toxicity toward warm-blooded animals. They are active against all or some stages of development of the pests and against resistant and normally sensitive species of the pests.
By controlling the animal pests, it is intended to prevent diseases and their transmission, mortality and decreasing performance (for example in the production of meat, milk, wool, hides, eggs), so that more economical and simpler animal keeping is possible, or so that in certain areas animal keeping is possible at all, by using the active compounds.
The pests include:
from the order of the Anoplura, for example, Haematopinus spp., Linognathus spp., Solenopotes spp., Pediculus spp., Pthirus spp.;
from the order of the Mallophaga, for example, Trimenopon spp., Menopon spp., Eomenacanthus spp., Menacanthus spp., Trichodectes spp., Felicola spp., Damalinea spp., Bovicola spp.;
from the order of the Diptera, for example, Chrysops spp., Tabanus spp., Musca spp., Hydrotaea spp., Muscina spp., Haematobosca spp., Haematobia spp., Stomoxys spp., Fannia spp., Glossina spp., Lucilia spp., Calliphora spp., Auchmeromyia spp., Cardylobia spp., Cochiomyia spp., Chrysomyia spp., Sarcophaga spp., Wohlfartia spp., Gasterophilus spp., Oesteromyia spp., Oedemagena sp., Hypoderma spp., Oestrus spp., Rhinoestrus spp., Melophagus spp., Hippobosca spp.
from the order of the Siphonaptera, for example, Ctenocephalides spp., Echidnophaga spp., Ceratophyllus spp.
from the order of the Metastigmata, for example, Hyalomma spp., Rhipicephalus spp., Boophilus spp., Amblyomma spp., Haemophysalis spp., Dermacentor spp., Ixodes spp., Argas spp., Ornithodorus spp., Otobius spp.;
from the order of the Mesostigmata, for example, Dermanyssus spp., Ornithonyssus spp., Pneumonyssus spp.
from the order of the Prostigmata, for example, Cheyletiella spp., Psorergates spp., Myobia spp., Demodex spp., Neotrombicula spp.;
from the order of the Astigmata, for example, Acarus spp., Myocoptes spp., Psoroptes spp., Chorioptes spp., Otodectes spp., Sarcoptes spp., Notoedres spp., Knemidocoptes spp., Neoknemidocoptex spp., Cytodites spp., Laminosioptes spp.
The livestock and breeding stock include mammals, such as, for example, cattle, sheep, goats, horses, pigs, dogs, cats, camels, water buffalo, donkeys, rabbits, fallow deer, reindeer, fur-bearing animals, such as, for example, minks, chinchilla or racoon, birds, such as, for example chickens, turkeys, pheasants, geese, ducks.
The laboratory and test animals include mice, rats, guinea pigs, golden hamsters, dogs and cats.
The pets include dogs and cats.
Administration can be effected prophylactically as well as therapeutically.
The active substances are administered, either directly or in the form of suitable preparations, enterally, parenterally, dermally, nasally, by treating the habitat or with the aid of shaped articles containing the active compound, such as, for example, strips, plates, tapes, collars, ear tags, limb bands or marking devices.
Enteral administration of the active compounds is effected for example orally in the form of powders, suppositories, tablets, capsules, drinks, granules, drenches, boluses, medicated feed or drinking water. Dermal application is effected, for example, in the form of dipping, spraying, bathing, washing, pouring-on and spotting-on, rubbing-in and powdering. Parenteral administration is effected, for example, in the form of injection (intramuscular, subcutaneous, intravenous or intraperitoneal) or by implants.
Suitable preparations include:
solutions, such as solutions for injection, oral solutions, concentrates for oral administration after dilution, solutions for use on the skin or in body cavities, pour-on formulations, gels;
emulsions and suspensions for oral or dermal administration and for injection; semi-solid preparations;
formulations in which the active compound is incorporated in a cream base or in an oil-in-water or water-in-oil emulsion base;
Solid preparations, such as powders, premixes or concentrates, granules, pellets, tablets, boluses, capsules; aerosols and inhalants, shaped articles containing the active compound.
Solutions for injection are administered intravenously, intramuscularly and subcutaneously.
Solutions for injection are prepared by dissolving the active compound in a suitable solvent and, if desired, adding additives, such as solubilizers, acids, bases, buffer salts, antioxidants, or preservatives. The solutions are sterile-filtered and decanted into containers.
Suitable solvents include: physiologically acceptable solvents, such as water, alcohols, such as ethanol, butanol, benzyl alcohol, glycerol, hydrocarbons, propylene glycol, polyethylene glycols and N-methylpyrrolidone, and their mixtures.
If appropriate, the active compounds can also be dissolved in physiologically acceptable vegetable or synthetic oils which are suitable for injection.
Suitable solubilizers include: solvents which facilitate the dissolution of the active compound in the main solvent or which prevent precipitation of the active compound.
Examples of solubilizers are polyvinylpyrrolidone, polyethoxylated castor oil and polyethoxylated sorbitan esters.
The following are preservatives: benzyl alcohol, trichlorobutanol, p-hydroxybenzoic esters or n-butanol.
Oral solutions are administered directly. Concentrates are first diluted to the administration concentration and then administered orally. Oral solutions and concentrates are prepared as described above in the case of the solutions for injection, sterile procedures not being necessary.
Solutions for use on the skin are applied drop by drop, smoothed on, rubbed in, splashed on or sprayed on, or applied by dipping, bathing or washing. These solutions are prepared as described above in the case of the solutions for injection.
It may be advantageous to add thickeners in the preparation process. The following are thickeners: inorganic thickeners, such as bentonites, colloidal silica, aluminium monostearate, or organic thickeners, such as cellulose derivatives, polyvinyl alcohols and their copolymers, acrylates and metacrylates.
Gels are applied to the skin or smoothed on or introduced into body cavities. Gels are prepared by adding such an amount of thickener to solutions which have been prepared as described for the solutions for injection that a clear composition is formed which has an ointment-like consistency. The thickeners used are the thickeners indicated further above.
Pour-on and spot-on formulations are poured or splashed onto limited areas of the skin, the active compound penetrating the skin and acting systemically or distributing itself over the surface of the body.
Pour-on and spot-on formulations are prepared by dissolving, suspending or emulsifying the active compound in suitable solvents or solvent mixtures which are tolerated by the skin. If appropriate, other auxiliaries, such as colorants, absorption promoters, antioxidants, photostabilizers or tackifiers are added.
Suitable solvents include: water, alkanols, glycols, polyethylene glycols, polypropylene glycols, glycerol, aromatic alcohols, such as benzyl alcohol, phenylethanol or phenoxyethanol, esters, such as ethyl acetate, butyl acetate or benzyl benzoate, ethers, such as alkylene glycol alkyl ethers, such as dipropylene glycol monomethyl ether or diethylene glycol mono-butyl ether, ketones, such as acetone or methyl ethyl ketone, aromatic and/or aliphatic hydrocarbons, vegetable or synthetic oils, DMF, dimethyl acetamide, N-methylpyrrolidone, or 2-dimethyl-4-oxy-methylene-1,3-dioxolane.
Colorants are all colorants which can be dissolved or suspended and which are approved for use in animals.
Examples of bioabsorption promoters are DMSO, spreading oils, such as isopropyl myristate, dipropylene glycol pelargonate, silicone oils, fatty acid esters, triglycerides or fatty alcohols.
The following are antioxidants: sulphites or metabisulphites, such as potassium metabisulphite, ascorbic acid, butylhydroxytoluene, butylhydroxyanisole or tocopherol.
Examples of photostabilizers are substances from the class of the benzophenones or novantisolic acid.
Tackifiers are, for example, cellulose derivatives, starch derivatives, polyacrylates or natural polymers such as alginates or gelatin.
Emulsions can be administered orally, dermally or as injections.
Emulsions are either the water-in-oil type or the oil-in-water type.
They are prepared by dissolving the active compound either in the hydrophobic or in the hydrophilic phase and by homogenizing this phase with the solvent of the other phase, with the aid of suitable emulsifiers and, if appropriate, other auxiliaries, such as colorants, bioabsorption promoters, preservatives, antioxidants, photostabilizers, and viscosity-increasing substances.
Suitable hydrophobic phases (oils) include: paraffin oils, silicone oils, natural vegetable oils such as sesame seed oil, almond oil or castor oil, synthetic triglycerides, such as caprylic/capric acid biglyceride, a triglyceride mixture with vegetable fatty acids of chain length C8-12 or other specifically selected natural fatty acids, mixtures of partial glycerides of saturated or unsaturated fatty acids which may also contain hydroxyl groups, and mono- and diglycerides of the C8/C10-fatty acids.
Fatty acid esters, such as ethyl stearate, di-n-butyryl adipate, hexyl laurate, dipropylene glycol pelargonate, esters of a branched fatty acid having a medium chain length with saturated fatty alcohols of chain length C16-C18, isopropyl myristate, isopropyl palmitate, caprylic/capric esters of saturated fatty alcohols of chain length C12-C18, isopropyl stearate, oleyl oleate, decyl oleate, ethyl oleate, ethyl lactate, waxy fatty acid esters such as artificial duck uropygial fat, dibutyl phthalate, dilsopropyl adipate, ester mixtures related to the latter, etc.
Fatty alcohols, such as isotridecyl alcohol, 2-octyldodecanol, cetylstearyl alcohol or oleyl alcohol.
Fatty acids, such as, for example, oleic acid and its mixtures.
Suitable hydrophilic phases include:
water, alcohols, such as, for example, propylene glycol, glycerol, sorbitol and their mixtures.
Suitable emulsifiers include:
nonionic surfactants, for example polyethoxylated castor oil, polyethoxylated sorbitan monooleate, sorbitan monostearate, glycerol monostearate, polyethoxy stearate or alkylphenol polyglycol ethers;
ampholytic surfactants, such as disodium N-lauryl-xcex2-iminodipropionate or lecithin;
anionic surfactants, such as Na lauryl sulfate, fatty alcohol ether sulphates, and the monoethanolamine salt of mono/dialkylpolyglycol ether orthophosphoric ester;
cationic surfactants, such as cetyltrimethylammonium chloride.
Other suitable auxiliaries include: substances which increase the viscosity and stabilize the emulsion, such as carboxymethylcellulose, methylcellulose and other cellulose and starch derivatives, polyacrylates, alginates, gelatin, gum arabic, polyvinyl-pyrrolidone, polyvinyl alcohol, methylvinyl ether/maleic anhydride copolymers, polyethylene glycols, waxes, colloidal silica, or mixtures of the listed substances.
Suspensions can be administered orally, dermally or as an injection. They are prepared by suspending the active compound in a liquid excipient, if appropriate with the addition of other auxiliaries, such as wetting agents, colorants, bioabsorption promoters, preservatives, antioxidants and photostabilizers.
Suitable liquid excipients include all homogeneous solvents and solvent mixtures.
Suitable wetting agents (dispersants) include the surfactants indicated further above.
Suitable other auxiliaries include those indicated further above.
Semi-solid preparations can be administered orally or dermally. They are only distinguished from the above-described suspensions and emulsions by their higher viscosity.
To prepare solid preparations, the active compound is mixed with suitable excipients, if appropriate with the addition of auxiliaries, and the mixture is formulated as desired.
Suitable excipients include all physiologically acceptable solid inert substances. Suitable for this purpose are inorganic and organic substances. Inorganic substances are, for example, common salt, carbonates, such as calcium carbonate, hydrogen carbonates, aluminium oxides, silicas, clays, precipitated or colloidal silica, and phosphates.
Organic substances are, for example, sugars, cellulose, foodstuffs and animal feeds, such as powdered milk, animal meals, cereal meals, coarse cereal meals and starches.
Auxiliaries are preservatives, antioxidants and colorants which have already been mentioned further above.
Other suitable auxiliaries are lubricants and glidants, such as, for example, magnesium stearate, stearic acid, talc, bentonites, disintegrants, such as starch or crosslinked polyvinylpyrrolidone, binders, such as, for example, starch, gelatin or linear polyvinylpyrrolidone, and dry binders, such as microcrystalline cellulose.
In the preparations, the active compounds can also be present in mixtures with synergists or other active compounds.
Ready-to-use preparations contain the active compound in concentrations of 10 ppm to 20% by weight, preferably from 0.1 to 10% by weight.
Preparations which are diluted before use contain the active compound in concentrations of 0.5 to 90% by weight, preferably from 5 to 50% by weight.
In general, it has been found to be advantageous to administer amounts of about 1 to 100 mg of active compound per kg of bodyweight per day to obtain effective results.